The present invention relates in general to a strip winding machine and in particular to a method of and a device for continuously balancing a changing load of a strip roll orbiting about an axis in the strip winding machine.
The invention is applicable especially in the strip winding machine of the type where the strip roll is arranged at one side of the axis only or where similar unequally loaded strip rolls are used for winding the strip around an electrical cable, especially in the production of high frequency co-axial cable.
In the case when two or more strips or tapes of metal, paper or plastic are simultaneously wound around a rope-like product such as a cable for example, the winding head of the machine is usually constructed such as to be in balanced condition during the winding process.
In the case when due to the construction of the processed cable only one strip or band is to be wound or when two strips are wound one after the other in opposite directions, this balance condition during the winding process does no longer take place; that means the winding head is operated at an imbalanced position.
The imbalance in unitarily loaded double head strip winding machines is usually compensated only partially by employing a counter balancing weight having half the weight of that of the head disk together with the strip roll supported on the latter. As a consequence, when the head disk is fully loaded the imbalance in the magnitude of a half head disk takes place at the side of the disk, whereas when the head disk becomes unloaded or empty the imbalance in the magnitude of half head disk occurs at the side of the counter balancing weight. This system is in a temporary balance only when a half of the strip load is unwound while in the remaining operational conditions an imbalance prevails which, particularly at large weights of the loaded head disk and at high rotational speeds, has extremely disturbing effects. The disturbances show themselves in the form of an increased non uniform wear in the bearings, an increased irregularity of rotary motion and the development of noise and vibrations. For these reasons the normal operational speed of unilaterally loaded strip winding machines has to be considerably reduced when larger weights of the strip rolls are employed.
This solution however, is very unsatisfactory inasmuch the utilization of the machine is inferior and the disturbing effects of the imbalance still strongly affect the quiet motion of the machine and the working life of its bearings in spite of the reduced rotary speed of the latter.
The aforementioned disadvantages are particularly critical in the case when the winding machines are installed in multi-floor production buildings because resultunt vibrations of the machine are transferred through the building and through the other production machinery and may cause interference with sensitive controlling and regulating units.